This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We developed a practical method for label-free quantification of specific molecules using spectroscopic imaging of sample-induced phase shifts. Diffraction phase microscopy equipped with various wavelengths of light source is used to record wavelength-dependent phase images. We performed dispersion measurements on pure solutions of single molecular species present in the cells, such as albumin and hemoglobin (Hb). With this prior calibration of molecular specific dispersion, we demonstrated the extraction of Hb concentration from individual red blood cells (RBCs). The end point of this study is non-invasive monitoring of physiological states of intact living cells.